TY - JOUR
T1 - The effect of liquid co-flow on gas fractions, bubble velocities and chord lengths in bubbly flows. Part II
T2 - Asymmetric flow configurations
AU - Muilwijk, Corné
AU - Van den Akker, Harry E.A.
PY - 2021
Y1 - 2021
N2 - This paper describes the effects of uniform and non-uniform liquid co-flow on the bubbly flow in a rectangular column (with two inlets) deliberately aerated unevenly. The two vertical bubbly streams, comprising uniform bubbles, started interacting downstream of the trailing edge of a splitter plate. This study quantifies the emergence of buoyancy driven flow patterns as a function of the degree of a-symmetric gas sparging and (non-)uniform liquid co-flow by using Bubble Image Velocimetry (BIV) and dual-tip optical fibre probes. Without liquid co-flow, small differences in the gas fraction of the left and right inlet had a large effect on the mixing pattern, whereas a liquid co-flow stabilized a homogeneous flow regime and the flow pattern was less sensitive to gas fraction differences. Void fractions, bubble velocities and chord lengths were measured at two fixed position in the flow channel, whereas BIV provided a global overview of the flow structures. A correlation was developed to predict (a-symmetric) operating conditions for which the gas fraction of the left and right inlet are balanced, such that the bubble motion is governed by advection and no buoyancy driven flow structures arise. The data obtained is highly valuable for CFD validation and development purposes.
AB - This paper describes the effects of uniform and non-uniform liquid co-flow on the bubbly flow in a rectangular column (with two inlets) deliberately aerated unevenly. The two vertical bubbly streams, comprising uniform bubbles, started interacting downstream of the trailing edge of a splitter plate. This study quantifies the emergence of buoyancy driven flow patterns as a function of the degree of a-symmetric gas sparging and (non-)uniform liquid co-flow by using Bubble Image Velocimetry (BIV) and dual-tip optical fibre probes. Without liquid co-flow, small differences in the gas fraction of the left and right inlet had a large effect on the mixing pattern, whereas a liquid co-flow stabilized a homogeneous flow regime and the flow pattern was less sensitive to gas fraction differences. Void fractions, bubble velocities and chord lengths were measured at two fixed position in the flow channel, whereas BIV provided a global overview of the flow structures. A correlation was developed to predict (a-symmetric) operating conditions for which the gas fraction of the left and right inlet are balanced, such that the bubble motion is governed by advection and no buoyancy driven flow structures arise. The data obtained is highly valuable for CFD validation and development purposes.
KW - Bubble Image Velocimetry
KW - CFD Validation
KW - Gas hold-up
KW - Inhomogeneous Bubble column
KW - Mixing pattern
KW - Optical fibre probe
UR - http://www.scopus.com/inward/record.url?scp=85102535832&partnerID=8YFLogxK
U2 - 10.1016/j.ijmultiphaseflow.2021.103562
DO - 10.1016/j.ijmultiphaseflow.2021.103562
M3 - Article
AN - SCOPUS:85102535832
SN - 0301-9322
VL - 138
JO - International Journal of Multiphase Flow
JF - International Journal of Multiphase Flow
M1 - 103562
ER -